Tardigrades.

[RAINCRAFTER]

Yep, I am starting a discussion thread about the creatures that survived highs and lows in temperature, radiation, and even space.

Talk away now, folks!

[Dartguy]

Looks like Rosie ODonnell

[Scotius]

Apparently that shapeless lump of proteins is evolution's golden boy. Let's send them to colonise Mars

[ChrisSpace]

I've known about these little things for a while. It's extraordinary to think that a complex organism like this can just happen to have all the capabilities to survive in space, just by pure evolutionary luck. I mean, there is no real advantage of a bug being able to survive in space if it just lives in water/dirt/mud/rock, so it is incredibly unlikely to have happened... yet it has. There are explanations of course, for example, sometimes the bugs don't have an open-air space to live in so they need another way to collect or store oxygen, or sometimes the bugs live in volcanic areas or glaciers that require lots of thermal shielding. But to have all the qualities in one bug, that is incredible.

[Pipcard]

They're also known as "water bears." Yeah, an eight-legged bear.

[KerikBalm]

Its not luck, and it wouldn't survive on mars in the long term.

It can survive being completely dried out

https://en.wikipedia.org/wiki/Trehalose#Biological_properties

"When tardigrades (water bears) dry out, the glucose in their bodies changes to trehalose when they enter a state called cryptobiosis  a state wherein they appear dead. However, when they receive water, they revive and return to their metabolic state. It is also thought that the reason the larvae of sleeping chironomid (Polypedilum vanderplanki) and artemia (sea monkeys, brine shrimp) are able to withstand dehydration is because they store trehalose within their cells."

Basically, they can be freeze dried.

In their freeze dried state, they can survive a lot... but they won't be growing or reproducing... they are metabolically inert... they'd be metabolically inert on mars.

Damage to their DNA (UV and other radiation sources) would accumulate with them unable to repair it.

After a while, they'd be unable to be revived.

Dead...

[grawl]

I mean, there is no real advantage of a bug being able to survive in space if it just lives in water/dirt/mud/rock, so it is incredibly unlikely to have happened... yet it has.

It's not the only bug to have survived in space, look at New Horizons **badoum tsha**

How was it discovered Tardigrades have survived space ? We found some in a meteorite fragment ?

[Luis]

How was it discovered Tardigrades have survived space ? We found some in a meteorite fragment ?

Tardigrades have been taken to space several times by NASA and ESA. Before that they had been pumped down to a hard vacuum in the lab on Earth. Aside from their ability to switch to spore mode to survive dessication, tardigrades' main survival advantage is that they have very simple bodies. Each species has a fixed number of cells that is the same for every individual in that species. This makes them more resistant to radiation because damaged cells can be replaced without turning into runaway tumours for example.

[RAINCRAFTER]

They're also known as "water bears." Yeah, an eight-legged bear.

Yeah, I call them that a lot more.

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How was it discovered Tardigrades have survived space ? We found some in a meteorite fragment ?

No, they were put outside the ISS. They lived for 13 days.

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I wonder if kerbals have similar DNA to these little critters?

[heng]

ok, they can survive being freeze dried, but they can't live that way.

they do need liquid water (and stuff) to reproduce...

so a sufficiently dedicated tardigrade could hitch a ride on a rocket, ride a probe to mars or jupiter or whereever... but it still needs to find suitable living conditions. it's no extremophile on itself.

we should make sure none of those are stowe-aways on any Europa mission

[KerikBalm]

ok, they can survive being freeze dried, but they can't live that way.

they do need liquid water (and stuff) to reproduce...

so a sufficiently dedicated tardigrade could hitch a ride on a rocket, ride a probe to mars or jupiter or whereever... but it still needs to find suitable living conditions. it's no extremophile on itself.

we should make sure none of those are stowe-aways on any Europa mission

Tardigrades would be the least of our worries, as they use oxygen, and are heterotrophs not autotrophs.

Put a tardigrade in a "sterile" environment*, and it will die eventually because it has nothing to eat.

Some bacteria though.... if its the right species or group of species, they'll proliferate all over the place and make "food" from available energy gradients.

Even if there is endogenous Europan life, its unlikely to be able to support tardigrades.

*sure, you can have a sterile environment with a lot of sterilized food... but eventually the food source will run out, and the targdigrade population will collapse.

[Technical Ben]

Apparently that shapeless lump of proteins is evolution's golden boy. Let's send them to colonise Mars

There was some erroneous data sent from the Curiosity rover. It required a reboot. I suspect it may have been a message. "We're here on Mars, looking for the others riding on Opportunity..."

[lajoswinkler]

Tardigrades are something I've been toying with at college a lot under the microscope, and sadly, one of the things basically everyone who heard of them by Internet received false information. They basically became a meme full of lies.

Much lies has been taught about these organisms. For example, about how they can live in space. No, they can not.

Or how they can survive indefinitively in space and be brought to life. No, they can not.

Or how they can be exposed to massive doses of ionizing radiation and all of them are still crawling around happy. No, they can not.

They are very tough, but by no means will they survive, let alone live in harsh environments. To live, a tardigrade needs relatively cozy environment.

They are funny unless you look at their mouth through an electron microscope.